1. MacCallum, P., Tolhurst, J. C., Buckle, G., and Sissons, H. A., J. Path. and Bact., 60, 93 (1948).
2. Gellerstedt, N., Acta path. et microbiol. Scandinav., 54, 574 (1944).
3. Englund, F., and Wahlgren, F., Nord. Med., 24, 2247 (1944).
4. Hollström, E. (personal communication).
5. Hellerström, S., Acta dermat.-venereol., 31, 194 (1951).